Limitations with cell cultures and experimental animal-based studies have had the scientific and industrial communities searching for new approaches that can provide reliable human models for applications such as drug development, toxicological assessment, and pre-clinical evaluation. This has resulted in the development of microfluidic-based cultures that may better represent organs and organ systems than conventional monolayer cell cultures. Although there is considerable interest from industry and regulatory bodies in this technology, several challenges need to be addressed for it to reach its full potential.
View Article and Find Full Text PDFWiley Interdiscip Rev Nanomed Nanobiotechnol
November 2023
Fluidic microphysiological systems (MPS) are microfluidic cell culture devices that are designed to mimic the biochemical and biophysical in vivo microenvironments of human tissues better than conventional petri dishes or well-plates. MPS-grown tissue cultures can be used for probing new drugs for their potential primary and secondary toxicities as well as their efficacy. The systems can also be used for assessing the effects of environmental nanoparticles and nanotheranostics, including their rate of uptake, biodistribution, elimination, and toxicity.
View Article and Find Full Text PDFThe development of antibiotic resistance among bacterial strains is a major global public health concern. To address this, drug-free antibacterial approaches are needed. Copper surfaces have long been known for their antibacterial properties.
View Article and Find Full Text PDFFront Cell Dev Biol
September 2021
Identification and approval of new drugs for use in patients requires extensive preclinical studies and clinical trials. Preclinical studies rely on experiments and animal models of human diseases. The transferability of drug toxicity and efficacy estimates to humans from animal models is being called into question.
View Article and Find Full Text PDFPumpless microfluidic systems are easy-to-use devices that can be used to culture cells that are sensitive to mechanical shear, such as lymphatic endothelial cells. However, previously developed pumpless systems either provide unidirectional shear where the cell culture medium is discarded, or bidirectional shear that produces endothelial cell cultures with disease characteristics. Here, we describe a PDMS-based system that produces cyclically rising and falling shear that is unidirectional, similar to what has been reported in lymphatic vessels.
View Article and Find Full Text PDFCarbon dots are biocompatible nanoparticles suitable for a variety of biomedical applications. Careful selection of carbon dot precursors and surface modification techniques has allowed for the development of carbon dots with strong near-infrared fluorescence emission. However, carbon dots that provide strong fluorescence contrast would prove even more useful if they were also responsive to stimuli.
View Article and Find Full Text PDFBackground: Decreasing the amount of liquid inside microphysiological systems (MPS) can help uncover the presence of toxic drug metabolites. However, maintaining near-physiological volume ratios among blood surrogate and multiple organ mimics is technically challenging. Here, we developed a body cube and tested its ability to support four human tissues (kidney, GI tract, liver, and bone marrow) scaled down from in vivo functional volumes by a factor of 73,000 with 80 μL of cell culture medium (corresponding to ~1/73000th of in vivo blood volume).
View Article and Find Full Text PDFACS Appl Bio Mater
October 2020
The lymphatic system is a complex organ system that is essential in regulating the development of host immune responses. Because of the complexity of the lymphatic system and the existence of few models that replicate human lymphatic vessels, there is a need for a primary cell-based lymphatic model that can provide a better understanding of the effects of flow parameters, therapeutics, and other stimuli on lymphatic vessel behavior. In this report, a fluidic device models the cyclical lymphatic flow under normal and disease conditions.
View Article and Find Full Text PDFMultiphoton polymer cross-linking evolves as the core process behind high-resolution additive microfabrication with soft materials for implantable/wearable electronics, tissue engineering, microrobotics, biosensing, drug delivery, Electrons and soft X-rays, in principle, can offer even higher resolution and printing rates. However, these powerful lithographic tools are difficult to apply to vacuum incompatible liquid precursor solutions used in continuous additive fabrication. In this work, using biocompatible hydrogel as a model soft material, we demonstrate high-resolution in-liquid polymer cross-linking using scanning electron and X-ray microscopes.
View Article and Find Full Text PDFWe have developed a pumpless cell culture chip that can recirculate small amounts of cell culture medium (400 μL) in a unidirectional flow pattern. When operated with the accompanying custom rotating platform, the device produces an average wall shear stress of up to 0.588 Pa ± 0.
View Article and Find Full Text PDFPhotoacoustic imaging has emerged as a promising imaging platform with a high tissue penetration depth. However, biodegradable nanoparticles, especially those for photoacoustic imaging, are rare and limited to a few polymeric agents. The development of such nanoparticles holds great promise for clinically translatable diagnostic imaging with high biocompatibility.
View Article and Find Full Text PDFCarbon dots have garnered attention for their strong multi-color luminescence properties and unprecedented biocompatibility. Despite significant progress in the recent past, a fundamental understanding of their photoluminescence and structure-properties relationships, especially at the bulk vs. single-particle level, has not been well established.
View Article and Find Full Text PDFExp Biol Med (Maywood)
November 2017
Integrated multi-organ microphysiological systems are an evolving tool for preclinical evaluation of the potential toxicity and efficacy of drug candidates. Such systems, also known as Body-on-a-Chip devices, have a great potential to increase the successful conversion of drug candidates entering clinical trials into approved drugs. Systems, to be attractive for commercial adoption, need to be inexpensive, easy to operate, and give reproducible results.
View Article and Find Full Text PDFBody-on-a-chip systems replicate the size relationships of organs, blood distribution and blood flow, in accordance with human physiology. When operated with tissues derived from human cell sources, these systems are capable of simulating human metabolism, including the conversion of a prodrug to its effective metabolite, as well as its subsequent therapeutic actions and toxic side-effects. The system also permits the measurement of human tissue electrical and mechanical reactions, which provide a measure of functional response.
View Article and Find Full Text PDFWe have developed an expandable modular body-on-a-chip system that allows for a plug-and-play approach with several in vitro tissues. The design consists of single-organ chips that are combined with each other to yield a multi-organ body-on-a-chip system. Fluidic flow through the organ chips is driven via gravity and controlled passively via hydraulic resistances of the microfluidic channel network.
View Article and Find Full Text PDFOrgan-on-a-chip devices have gained attention in the field of in vitro modeling due to their superior ability in recapitulating tissue environments compared to traditional multiwell methods. These constructed growth environments support tissue differentiation and mimic tissue-tissue, tissue-liquid, and tissue-air interfaces in a variety of conditions. By closely simulating the in vivo biochemical and biomechanical environment, it is possible to study human physiology in an organ-specific context and create more accurate models of healthy and diseased tissues, allowing for observations in disease progression and treatment.
View Article and Find Full Text PDFWe have developed a low-cost liver cell culture device that creates fluidic flow over a 3D primary liver cell culture that consists of multiple liver cell types, including hepatocytes and non-parenchymal cells (fibroblasts, stellate cells, and Kupffer cells). We tested the performance of the cell culture under fluidic flow for 14 days, finding that hepatocytes produced albumin and urea at elevated levels compared to static cultures. Hepatocytes also responded with induction of P450 (CYP1A1 and CYP3A4) enzyme activity when challenged with P450 inducers, although we did not find significant differences between static and fluidic cultures.
View Article and Find Full Text PDFTransepithelial/transendothelial electrical resistance (TEER) is a widely accepted quantitative technique to measure the integrity of tight junction dynamics in cell culture models of endothelial and epithelial monolayers. TEER values are strong indicators of the integrity of the cellular barriers before they are evaluated for transport of drugs or chemicals. TEER measurements can be performed in real time without cell damage and generally are based on measuring ohmic resistance or measuring impedance across a wide spectrum of frequencies.
View Article and Find Full Text PDFThe use of nanoparticles in medical applications is highly anticipated, and at the same time little is known about how these nanoparticles affect human tissues. Here we have simulated the oral uptake of 50 nm carboxylated polystyrene nanoparticles with a microscale body-on-a-chip system (also referred to as multi-tissue microphysiological system or micro Cell Culture Analog). Using the 'GI tract-liver-other tissues' system allowed us to observe compounding effects and detect liver tissue injury at lower nanoparticle concentrations than was expected from experiments with single tissues.
View Article and Find Full Text PDFHeart valve disease is an increasing clinical burden for which there is no effective treatment outside of prosthetic replacement. Over the last 20 years, clinicians have increasingly preferred the use of biological prosthetics to mechanical valves despite their superior durability because of the lifelong anticoagulation therapy that is required. Mechanical valve surface engineering has largely focused on being as non-thrombogenic as possible, but despite decades of iteration has had insufficient impact on the anticoagulation burden.
View Article and Find Full Text PDFThe continued development of in vitro systems that accurately emulate human response to drugs or chemical agents will impact drug development, our understanding of chemical toxicity, and enhance our ability to respond to threats from chemical or biological agents. A promising technology is to build microscale replicas of humans that capture essential elements of physiology, pharmacology, and/or toxicology (microphysiological systems). Here, we review progress on systems for microscale models of mammalian systems that include two or more integrated cellular components.
View Article and Find Full Text PDFA multiorgan, functional, human in vitro assay system or 'Body-on-a-Chip' would be of tremendous benefit to the drug discovery and toxicology industries, as well as providing a more biologically accurate model for the study of disease as well as applied and basic biological research. Here, we describe the advances our team has made towards this goal, as well as the most pertinent issues facing further development of these systems. Description is given of individual organ models with appropriate cellular functionality, and our efforts to produce human iterations of each using primary and stem cell sources for eventual incorporation into this system.
View Article and Find Full Text PDFMulti-organ microdevices can mimic tissue-tissue interactions that occur as a result of metabolite travel from one tissue to other tissues in vitro. These systems are capable of simulating human metabolism, including the conversion of a pro-drug to its effective metabolite as well as its subsequent therapeutic actions and toxic side effects. Since tissue-tissue interactions in the human body can play a significant role in determining the success of new pharmaceuticals, the development and use of multi-organ microdevices present an opportunity to improve the drug development process.
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